Lesson 2 | The Structure of Atoms - Ms. Holm...

Lesson 2 | The Structure of Atoms

Student Labs and Activities Page Appropriate For:Launch Lab 25 all studentsContent Vocabulary 26 all studentsLesson Outline 27 all studentsMiniLab 29 all studentsContent Practice A 30

Content Practice B 31

Language Arts Support 32 all studentsMath Skills 34 all studentsSchool to Home 35 all studentsKey Concept Builders 36

Enrichment 40 all studentsChallenge 41

Lab A 44

Lab B 47

Lab C 50

Chapter Key Concepts Builder 51

AssessmentLesson Quiz A 42

Lesson Quiz B 43

Chapter Test A 52

Chapter Test B 55

Chapter Test C 58

Approaching Level On Level Beyond Level English-Language Learner

Teacher evaluation will determine which activities to use or modify to meet any student’s proficiency level.

24 Matter and Atoms

Name Date Class

LESSON 2: 20 minutes

How can you make different things from the same parts?Atoms are all made of the same parts. Atoms can be different from each other because theyhave different numbers of these parts. In this lab, you will investigate how you can makethings that are different from each other even though you use the same parts to make them.

Procedure1. Read and complete a lab safety form.

2. Think about how you can join paperclips, toothpicks, and string tomake different types of objects. Youmust use at least one of each item, butnot more than five of any kind.

3. Make the object. Use tape to connectthe items.

4. Plan and make two more objects usingthe same three items, varying thenumbers of each item.

5. In the Data and Observations sectionbelow, describe how each of the objectsyou made are alike and different.

Data and Observations

Think About This1. Observe What do the objects you made have in common? In what ways are they

different?

2. Key Concept What effect do you think increasing or decreasing the number ofitems you used would have on the objects you made?

Matter and Atoms 25

Launch Lab

Name Date Class

LESSON 2

The Structure of AtomsDirections: Use the terms below to complete the concept map. NOTE: You may need to change a term to itsplural form.

atomic number charge electron electron cloud ionisotope neutron nucleus proton

26 Matter and Atoms

Content Vocabulary

8.

5.

3.

7.

4.

1.

6.

2.

9.

that have gained or lostelectrons become

which have a positiveor negative

have a central regioncalled

have a regionsurrounding the

central area called

the number of these isthe same as the atom’s

have the same number ofthese compared with otheratoms of the same element

have different number of thesecompared with other atoms ofthe same element

which contains particles called which contains particlescalled

atoms

Name Date Class

LESSON 2

The Structure of AtomsA. The Parts of an Atom

1. Every kind of element is made up of its own kind of .

2. Atoms are composed of several basic types of very small ; the of each of theseparticles gives the different kinds of atoms their unique identity.

3. The region at the center of an atom that contains most of the mass of the atom is

called the .

a. A positively charged particle in the nucleus of an atom is called

a(n) .

b. An uncharged particle in the nucleus of an atom is called

a(n) .

4. A negatively charged particle that occupies the space in an atom outside the

nucleus is called a(n) .

a. are much smaller in size than

and neutrons, and they move very quickly.

b. The region surrounding an atom’s nucleus where one or more electrons are most

likely to be found is called a(n) .

c. An electron cloud is mostly made up of space; it is

not a cloud of .

d. The electrons closest to the have the least energy; the

electrons farthest from the have the most energy.

B. The Size of Atoms

1. All the substances around you, including your body and the air you breathe are

made up of millions and millions of .

2. If you could enlarge an atom to be 1 million times larger than its natural size, it

would be the size of a(n) ; this object enlarged to the

same degree would be the size of .

Matter and Atoms 27

Lesson Outline

Name Date Class

Lesson Outline continued

C. Differences in Atoms

1. Every atom has a(n) charged nucleus surrounded by

a(n) charged electron cloud; however, atoms can have

different numbers of , neutrons, and electrons.

2. The number of protons in the nucleus of an atom of an element is called

the .

a. Each has a different atomic number.

b. The number of in the nucleus of the atomdetermines the identity of the atom.

3. One of two or more atoms of an element having the same number of protons but

a different number of neutrons is called a(n) .

4. A neutral atom has the same number of in its nucleus

as in its electron cloud.

a. A neutral atom can gain one or more , giving theatom a(n) charge; a neutral atom can lose one ormore , giving the atom a(n) charge.

b. An atom that has a charge because it has gained or lost electrons is called

a(n) .

c. Ions have same number of and are the same elementthey were before gaining or losing electrons.

D. Atoms and Matter

1. All atoms of the same element have the same number

of .

2. For each element, the number of and the number of

can vary.

3. The properties of an element and the ways its combineare determined mainly by the number and the arrangement of the in its atoms.

28 Matter and Atoms

Name Date Class

LESSON 2: 20 minutes

How can you model atoms?You can use models to study parts of atoms.

Procedure1. Read and complete a lab safety form.

2. Fill in the blanks in the table shownin the Data and Observations sectionbelow.

Do not eat any food you use for

a lab.

3. Use pieces of toothpicks and coloredmarshmallows to model the nucleusof an atom of each element. Use pinkfor protons and green for neutrons.

4. On a desk, use yellow marshmallows tosurround each nucleus with electrons.

Data and Observations

Element Protons Neutrons Electrons

Boron 5 6

5 4

Carbon 6 6

2 2

Nitrogen 7 6

Analyze and Conclude1. Decide Which model element’s atomic number is greatest? How do you know?

2. Key Concept What would change if the last model element had eight protons?

Matter and Atoms 29

MiniLab

Name Date Class

LESSON 2

The Structure of AtomsDirections: On the line before each definition, write the letter of the term that matches it correctly. Each term isused only once.

1. positively charged particle in the nucleus ofan atom

2. region surrounding an atom’s nucleus where oneor more electrons are often found

3. negatively charged particle that occupies thespace in an atom outside the nucleus

4. one or more atoms of an element having thesame number of protons but a different numberof neutrons

5. region at the center of an atom that containsmost of the mass of an atom

6. an atom that has a charge because it has gainedor lost electrons

7. the number of protons in the nucleus of an atomof an element

8. uncharged particle in the nucleus of an atom

A. atomic number

B. electron

C. electron cloud

D. ion

E. isotope

F. nucleus

G. neutron

H. proton

30 Matter and Atoms

Content Practice A

Name Date Class

LESSON 2

The Structure of AtomsDirections: Circle the term in parentheses that correctly completes each sentence.

1. The nucleus of an atom contains (protons/electrons) and neutrons.

2. The nucleus has a (positive charge/negative charge) and the (least mass/most mass)of the atom.

3. An electron is a (positively charged/negatively charged) particle located outside the nucleus.

4. The modern model of an atom is called the (electron-cloud/nucleus-orbit) model.

5. Electrons that are close to the nucleus have (more energy/less energy) than electronsthat are farther from the nucleus.

6. The atomic number is the number of (protons/neutrons) in the nucleus of an atomof an element.

7. Isotopes have the same number of protons but different numbers of (electrons/neutrons).

8. An ion has a charge because it has gained or lost (protons/electrons).

9. A (positive/negative) ion has more protons than electrons.

10. Adding a(n) (proton/electron) to a neutral atom produces a new element.

Matter and Atoms 31

Content Practice B

Name Date Class

LESSON 2

Word-Meaning Activity: Using AntonymsWords with opposite meanings are called antonyms. For example, the words hot and coldare antonyms.

Directions: On the line before each word in the numbered column, write the letter of the correct antonym.

1. part

2. substance

3. positive

4. proton

5. heterogeneous

6. individual

7. solvent

8. element

9. bond

A. negative

B. compound

C. multiple

D. solute

E. mixture

F. homogeneous

G. whole

H. electron

I. detach

32 Matter and Atoms

Language Arts Support

Language Arts Support

Name Date Class

LESSON 2

Word-Meaning Activity: Using Scientific WordsDirections: Study the terms and definitions below. On the line before each definition, write the letter of the termthat matches it correctly. Not all terms are used. NOTE: You may need to change a term to its plural form.

A. atom n. a small particle that is the building block of matter

B. electron n. negatively charged component of an atom

C. proton n. positively charged component of an atom

D. neutron n. uncharged component of an atom

E. ion n. an atom with a charge

F. nucleus n. the center part of an atom

G. electron cloud n. the outer part of an atom

1. Isotopes have the same number of protons as other atoms of the same element,

but different numbers of .

2. Protons and neutrons are found in an atom’s .

3. Electrons are found in an atom’s , which is mostlyempty space.

4. An element is made up of just one type of .

5. Na+ is an example of a(n) .

6. The negative charges of an atom’s electrons are balanced by the atom’s

.

Matter and Atoms 33

Name Date Class

LESSON 2

Use Scientific NotationMeasurements of atoms, such as amounts, distances, and weights, are often very large orvery small when compared to measurements of things you can see or touch. Scientificnotation represents numbers as a power of 10. This makes very large or small numberseasier to use and understand.

Approximately 7,500,000,000,000 carbon atoms fit across the period that you make withyour pencil. Express this number in scientific notation.

Step 1 Rewrite the number with a decimal after the first nonzero digit.7.500000000000

Step 2 Find the number of places and the direction you moved the decimal. If a numberdoes not show a decimal, the decimal is at the right end of the number.You moved the decimal 12 places to the left.

Step 3 Drop the zeros, and write the number of places you moved the decimal as a powerof 10. If you moved the decimal to the right, the power is negative. If you movedthe decimal to the left, the power is positive.7.5 × 1012

Step 4 Reverse the process to change scientific notation back to a whole number. Apositive power of 10 moves the decimal to the right. A negative power of 10 movesthe decimal to the left.

Practice1. A sample of gold contains

3,800,000,000,000,000,000 atoms.Express this number in scientificnotation.

2. A sample of silver contains400,000,000,000,000 atoms. Expressthis number in scientific notation.

3. A sample of carbon has a mass of0.000000000000000000034 kg. Expressthis mass in scientific notation.

4. A sample of silicon contains5.23 × 1011 atoms. Write this amountas a whole number.

5. The mass of a proton is about1.67 × 10−27 kg. Write this mass as awhole number.

34 Matter and Atoms

Math Skills

Name Date Class

LESSON 2

The Structure of AtomsDirections: Use your textbook to respond to each statement.

1. All atoms have the same basic structure. The nucleus is the center regionof the atom.

Describe the nucleus by identifying the particles that are inside of it, its overall charge,and its mass compared to the mass of an atom.

2. Electrons are one of the components of atoms. They are found in a regionof the atom called the electron cloud.

Describe electrons by identifying their charge and their relative mass compared to theatom as a whole.

3. Elements are arranged in the periodic table in order of their atomic numbers.

Identify what can be learned about an atom of an element if its atomic number isknown.

4. Although every atom of an element has the same number of protons, theatoms of an element can vary in other ways.

Identify how atoms can vary and what these types of atoms are called.

5. Atoms of an element can gain or lose electrons. An atom that has gained orlost electrons is called an ion.

Describe how gaining an electron changes the overall charge on an atom.

Matter and Atoms 35

School to Home

Name Date Class

LESSON 2

The Structure of AtomsKey Concept Where are protons, neutrons, and electrons located in an atom?

Directions: Label this diagram by writing the correct term on each line.

Directions: Answer each question or respond to each statement on the lines provided.

4. Which particle in an atom has a positive charge?

5. Which particle in an atom has no charge?

6. Which particle in an atom has a negative charge?

7. Where is most of the mass of an atom found?

8. Describe the structure of the atom in the diagram above. How many of each type ofparticle does the atom have?

36 Matter and Atoms

Key Concept Builder

1.

2.

3.

Name Date Class

LESSON 2

The Structure of AtomsKey Concept How is the atomic number related to the number of protons in an atom?

Directions: On each line, write the term or phrase that correctly completes each sentence.

1. The is the number of protons in the nucleus of an atom ofan element.

2. You can identify an element if you know its atomic number or

3. In the periodic table, the atomic number of an element is the

above its symbol.

Directions: Complete the chart with the correct numbers on the lines provided.

Element Atomic Number Number of Protons Number of Electrons

magnesium 12 4. 5.

carbon 6. 6 6

oxygen 8 7. 8.

Key Concept Builder

Matter and Atoms 37

Name Date Class

LESSON 2

The Structure of AtomsKey Concept What effect does changing the number of particles in an atom have on the

atom’s identity?

Directions: Complete the chart with the correct terms or numbers from the word bank on the lines provided.Some terms or numbers may be used more than once or not at all.

isotope negative ion new element positive ion5 6 7 8 9 10 11 12

Possible Changes in Atoms

Neutron Atom Change Results

carbon6 protons6 neutrons6 electrons

add one proton 1. 2. protons3. neutrons4. electrons


add one neutron 5. 6. protons

7. neutrons8. electrons


add one electron 9. 10. protons

11. neutrons12. electrons


lose one electron 13. 14. protons15. neutrons

16. electrons

38 Matter and Atoms

Key Concept Builder

Name Date Class

LESSON 2

The Structure of AtomsKey Concept What effect does changing the number of particles in an atom have on the

atom’s identity?

Directions: On the line before each statement, write the letter of the correct answer.

1. Changing the number of protons in an atom makesA. an ion.B. an isotope.C. a new element.

2. If an atom has 6 protons, 6 neutrons, and 6 electrons, its isotope would have adifferent number ofA. protons.B. neutrons.C. electrons.

3. An atom with the same number of protons and electrons has aA. neutral charge.B. positive charge.C. negative charge.

4. An atom that has a charge because it has gained or lost electrons isA. an ion.B. an isotope.C. a new element.

5. A positive ion has moreA. protons than electrons.B. electrons than protons.C. neutrons than protons.

6. A negative ion has moreA. protons than electrons.B. electrons than protons.C. neutrons than protons.

7. The number of electrons in atoms can change when elements combine to formA. isotopes.B. molecules.C. compounds.

Matter and Atoms 39

Key Concept Builder

Name Date Class

LESSON 2

Properties of IsotopesYou have learned that isotopes are atoms

of the same element with different numbersof neutrons. The simplest element, hydrogen,has three isotopes. The most commonisotope has no neutrons at all. A hydrogenisotope called deuterium has one neutron.The third, tritium, has two neutrons.

To distinguish between isotopes, you canwrite the symbol like this: AXZ. X is thesymbol of the atom. A is the atomic number(number of protons) and Z is the massnumber (total number of protons andneutrons). For hydrogen, the three isotopeswould be written as follows: 1H1 (ordinaryhydrogen), 1H2 (deuterium), 1H3 (tritium).

You can use these symbols to figure outhow many neutrons an isotope has. Themass number is the total number of protonsand neutrons. Subtract the atomic numberfrom the mass number to get the number ofneutrons. For example, 17Cl35 is the symbolfor an isotope of chlorine. The isotope has17 protons and 18 (35–17) neutrons.

How many neutrons?How many neutrons can an atom have?

Lighter elements tend to have about thesame number of protons as neutrons.Elements that have more protons tend toneed more neutrons to keep them stable.

Stable and Unstable IsotopesSome combinations of protons and

neutrons produce a stable atom. For

example, ordinary hydrogen is very stable.It makes up about 99.98% of all thehydrogen found in nature.

If an atom has too few or too manyneutrons, it becomes unstable. This meansthat the nucleus of the atom decays orchanges. Unstable isotopes, such as tritium,are said to be radioactive because they giveoff small particles or energy as they decay.

Uses of Radioactive IsotopesIsotopes of the same element have similar

properties because they have the samenumber of protons and electrons. However,they give off radiation that can be sensed byinstruments. For example, if a small numberof regular phosphorus atoms in fertilizer arereplaced with radioactive phosphorusisotopes, scientists can trace the path of thefertilizer through a plant. Doctors use similarisotopes to trace the path of nutrients ormedicines through the body.

Exposing foods to some radioactiveisotopes kills harmful bacteria. This makes thefood safer to eat and keeps it from spoiling asfast. Isotopes can also slow the ripeningprocess in fruits and vegetables so the foodcan be transported long distances.

Radioactive isotopes have many otheruses, from smoke detectors to determiningthe age of objects. They have also shownpromise in destroying cancer cells andhelping to treat other medical conditions.

Applying Critical-Thinking SkillsDirections: Answer each question or respond to each statement.

1. Calculate How many neutrons are in the following isotopes: 8O18 and 47Ag108?

2. Evaluate Would you eat foods irradiated with radioactive isotopes? Why or why not?

Enrichment

40 Matter and Atoms

Name Date Class

LESSON 2

Modeling AtomsThe first person to use the word atom was a Greek philosopher named Democritus in

about 400 B.C. The word atom means “indivisible.” Since that time, many scientists havecontributed to our knowledge of the structure of the atom. They include John Dalton,J.J. Thomson, Ernest Rutherford, Niels Bohr, and others. Each of these scientists proposed amodel to explain the structure of atoms.

Make a Time Line of the Milestones in Atomic TheoryResearch the history of the atom. On poster board, draw a time line showing when each

of the major changes in atomic theory took place. Include all the people mentioned aboveand at least two other scientists who contributed to our understanding of the atom. Illustrateyour time line with pictures of what the models of atoms looked like at each stage in history.When you are finished, share what you have learned with the class by displaying your posteror giving an oral presentation.

Matter and Atoms 41

Challenge

Name Date Class

LESSON 2

The Structure of AtomsMatchingDirections: On the line before each definition, write the letter of the term that matches it correctly. Each term isused only once.

Matching Set 1 1. positively charged particle in the nucleus of

an atom

2. negatively charged particle that occupies thespace in an atom outside the nucleus


Matching Set 2

4. one of two or more atoms of an element thathave different numbers of neutrons

5. region at the center of an atom

6. an atom that has a positive or negative charge

A. electron

B. neutron

C. proton

D. nucleus

E. ion

F. isotope

Multiple ChoiceDirections: On the line before each question or statement, write the letter of the correct answer.

7. An element’s atomic number tells how many are in the nucleus of anatom of that element.A. protonsB. neutronsC. electrons

8. Where is an atom’s electron cloud located?A. inside the nucleusB. outside of the atomC. surrounding the nucleus

42 Matter and Atoms

Lesson Quiz A

Name Date Class

LESSON 2

The Structure of AtomsMatchingDirections: On the line before each definition, write the letter of the term that matches it correctly. Not all termsare used.

1. The part of an atom that contains most ofits mass

2. particle in the nucleus of an atom that has apositive charge

3. particle of an atom that has a negative charge

4. an atom that has a positive or negative charge


6. one of two or more atoms of an element thathave different numbers of neutrons

A. electron

B. nucleus

C. neutron

D. electron cloud

E. ion

F. isotope

G. proton

Multiple ChoiceDirections: On the line before each statement, write the letter of the correct answer.

7. An element’s atomic number tells the number ofA. isotopes it forms.B. protons in the nucleus.C. particles in the nucleus.D. electrons it gains to form an ion.

8. In an atom, electronsA. are paired with protons.B. are found within the nucleus.C. stay in a region called the electron cloud.D. orbit the nucleus like planets around the Sun.

Matter and Atoms 43

Lesson Quiz B

Name Date Class

50 minutes

Balloon MoleculesKnowing how atoms join to form the smallest parts of a compound can be useful. It cansometimes help you predict properties of compounds. It also can help you understand howcompounds combine to form mixtures. In this lab, you will connect small balloons to makemodels of molecules.

Ask a QuestionHow do atoms combine to make molecules?

Materialssmall balloonstapeblack markerindex cards

SafetyMake Observations

1. Read and complete a lab safety form.

2. Look at the molecule models in the table below. Each molecule is made of two ormore atoms. Each type of atom is drawn in a different color.

3. Notice that a water molecule—H2O—consists of two hydrogen atoms and oneoxygen atom.

44 Matter and Atoms

Lab A

Name Date Class

4. Inflate three balloons as models of the three atoms that make up a water molecule.

Choose one color for the two hydrogen atoms and a different color for theoxygen atom.

Inflate each balloon until it is about 4 cm wide.

5. Look at the shape of the water molecule in the table.

Use tape to connect your model atoms in that shape.

6. Use a black marker to write H on each hydrogen balloon and O on the oxygen balloon.

7. Write Water H2O on an index card, and place the card next to your model.

8. Look at the molecules in the table. Choose three molecules that you would like tomodel. Notice the types of atoms that make up the molecules you have chosen to model.

9. Choose a different color balloon for each type of atom. If possible, use the samecolors for hydrogen and oxygen that you used for your water molecule.

10. Use tape to connect the atoms in the same arrangements shown in the table.

Then use a marker to write the chemical symbol of each element on the balloonfor that type of atom.

11. Label an index card for each molecule, just as you did for the water molecule.

Display each of your models together.

Lab Tips• When making your models, it is best to have all the balloons inflated to the same size,

but keep in mind that real atoms have different diameters.• Press down lightly when writing the chemical symbols on the model atoms to avoid

popping the balloons.

Analyze and Conclude12. Analyze Which, if any, of the molecules you modeled represent the smallest particles

of a substance?

Which, if any, represent the smallest particles of an element?

Explain.

Matter and Atoms 45

Lab A continued

Name Date Class

13. The Big Idea How do the molecules you modeled depend on atoms?

Communicate Your ResultsUse a digital camera to take photographs of each modelyou made. Then, use the photos to make a computerpresentation explaining the atoms that join to make eachmolecule you modeled.

46 Matter and Atoms

Lab A continued

Name Date Class

50 minutes

Balloon MoleculesKnowing how atoms join to form the smallest parts of a compound can be useful. It cansometimes help you predict properties of compounds. It also can help you understand howcompounds combine to form mixtures. In this lab, you will connect small balloons to makemodels of molecules.

Ask a QuestionHow do atoms combine to make molecules?

Materialssmall balloons

tapeblack marker

index cards

Safety

Make Observations1. Read and complete a lab safety form.

2. Look at the molecule models in the table below. Each molecule is made of two or moreatoms. Each type of atom is drawn in a different color.

3. Notice that a water molecule—H2O—consists of two hydrogen atoms and one oxygenatom.

Matter and Atoms 47

Lab B

Name Date Class

4. Inflate three balloons as models of the three atoms that make up a water molecule.Choose one color for the two hydrogen atoms and a different color for the oxygenatom. Inflate each balloon until it is about 4 cm wide.

5. Look at the shape of the water molecule in the table. Use tape to connect your modelatoms in that shape.

6. Use a black marker to write H on each hydrogen balloon and O on the oxygen balloon.

7. Write Water H2O on an index card, and place the card next to your model.

8. Look at the molecules in the table. Choose three molecules that you would like to model.Notice the types of atoms that make up the molecules you have chosen to model.

9. Choose a different color balloon for each type of atom. If possible, use the same colorsfor hydrogen and oxygen that you used for your water molecule.

10.Use tape to connect the atoms in the same arrangements shown in the table. Then usea marker to write the chemical symbol of each element on the balloon for that type ofatom.

11.Label an index card for each molecule, just as you did for the water molecule. Displayeach of your models together.

Lab Tips• When making your models, it is best to have all the balloons inflated to the same size,

but keep in mind that real atoms have different diameters.

• Press down lightly when writing the chemical symbols on the model atoms to avoidpopping the balloons.

Analyze and Conclude12. Analyze Which, if any, of the molecules you modeled represent the smallest particles

of a substance? Which, if any, represent the smallest particles of an element? Explain.

13. The Big Idea How do the molecules you modeled depend on atoms?

48 Matter and Atoms

Lab B continued

Name Date Class

Communicate Your ResultsUse a digital camera to take photographs of each model youmade. Then, use the photos to make a computer presentationexplaining the atoms that join to make each molecule youmodeled.

Make models for the other compounds shown in this chapter, including any that you didnot previously make in the table on the previous page. Remember that the smallest partsof some compounds, such as NaCl, are not molecules because the same atoms do notalways travel together. You can still model these particles as long as you keep in mind thatthey are not called molecules.

Matter and Atoms 49

Lab B continued

Extension

Name Date Class

Invent Your Own MoleculesDirections: Use the information and data from the Lab Balloon Molecules to perform this lab.

You have learned that molecules are made up of atoms joined together in various ways. InLab B, you used balloons to make models of molecules. Use balloons of your choice toinvent and model some additional molecules. Research to find out whether each moleculeyou made actually exists. If it does, name it.

Please note that you must complete Lab B before beginning Lab C. Also, have your teacherapprove your design and safety procedures before beginning your experiment.

50 Matter and Atoms

Lab C

Name Date Class

Matter and AtomsEnd-of-Chapter PracticeDirections: Work with a group to create a poster about the elements found in common items.

Use a copy of the periodic table and select one row to study in more depth. Classify theelements in your row as metals, metalloids, or nonmetals.

Metals: Metalloids: Nonmetals:

Assign at least one element to each group member. Then answer the following questions:

My Element:

What common items are madefrom or contain my element?

What interesting facts can I find about my element?

As a group, compile your results and make the following decisions:

What form will our poster take? What materials will we need? Who will perform which tasks?

Share your poster with the class. Then hang your poster in your classroom or in the hallway.

Display requirements:• organized in logical manner• includes common items made from or containing elements

• includes interesting facts about elements• includes contributions from all group members

Matter and Atoms 51

Chapter Key Concepts Builder

Name Date Class

Matter and AtomsMultiple ChoiceDirections: On the line before each question or statement, write the letter of the correct answer.

1. A solvent and one or more solutes make up aA. compound.B. homogeneous mixture.C. heterogeneous mixture.

2. Which term represents the combination of atoms that make up a compound?A. atomic numberB. chemical symbolC. chemical formula

3. How are protons and neutrons alike?A. Both are in the nucleus.B. Both are charged particles.C. Both have less mass than an electron.

4. The electrons closest to an atom’s nucleus have less than those furtheraway.A. massB. chargeC. energy

5. An atom that has the same number of protons and electrons hasA. no charge.B. a positive charge.C. a negative charge.

6. Elements and compounds areA. mixtures.B. solutions.C. substances.

7. A compound made from two elements will haveA. all the properties of both elements.B. all the properties of one of the elements.C. different properties than either element.

Chapter Test A

52 Matter and Atoms

Name Date Class

CompletionDirections: One each line, write the term from the word bank that correctly completes each sentence. Each termis used only once.

compound element heterogeneous mixture homogeneous mixture

8. The parts of a(n) are evenly mixed but not bonded together.

9. A(n) such as table salt contains two or more substances ina specific combination.

10. In a(n) , the individual components are not evenly mixed.

11.Pure gold is an example of a(n) .

Interpreting a DiagramDirections: Complete this concept map by choosing terms from the word bank and writing them in the correctspaces. Each term is used only once.

atomic number ions isotopes neutrons protons

Chapter Test A continued

The atoms of a particular

element

always have the samenumber of

12. ,

14. . 15. . 16. ,

13. electrons,

can gain or lose that have differentnumbers of

which is the same as itswhich results in the

formation of are called

Matter and Atoms 53

Name Date Class

Short AnswerDirections: Respond to each statement on the lines provided.

17. Identify one way that homogeneous mixtures and heterogeneous mixtures are different.

18. Describe an atom’s electron cloud using your own words.

19. Define Use the word elements in a definition of the word compound.

Concept ApplicationDirections: Answer each question or respond to each statement on the lines provided. Use complete sentences.

20. Predict The atomic number of iron is 26. What can you predict about iron atoms usingthis information?

21. List and describe three different methods that can be used to separate the componentsof a mixture.

54 Matter and Atoms

Chapter Test A continued

Name Date Class


1. Which one is NOT a solution?A. airB. brassC. salt waterD. fruit salad

2. A chemical formula can be used to determineA. the number of protons in an atom.B. the size of the atoms in a compound.C. the number of isotopes an element has.D. the combination of atoms in a compound.

3. Which parts of an atom are in the nucleus?A. neutrons onlyB. neutrons and protonsC. electrons and protonsD. electrons and neutrons

4. Which statement is true about solutions?A. Solutes are evenly mixed in solutions.B. There must be at least three components.C. The solvent or one of the solutes must be liquid.D. Solvents and solutes are present in equal amounts.

5. A neutral, or uncharged, atom definitely has the same number ofA. neutrons and protons.B. protons and electrons.C. electrons and neutrons.D. protons, neutrons, and electrons.

6. The properties of a sample of a compound made from two elementsA. are all the properties of both elements.B. are the exact same as the properties of one of the elements.C. are variable, depending upon the composition of the sample.D. are different from the properties of either element that makes it up.

Matter and Atoms 55

Chapter Test B

Name Date Class

CompletionDirections: One each line, write the term from the word bank that correctly completes each sentence. Not allterms are used.

atom compound element

heterogeneous mixture homogeneous mixture nucleus

7. The parts of a(n) are evenly mixed but not bondedtogether.




Interpreting a DiagramDirections: Complete this concept map by choosing terms from the word bank and writing them in the correctspaces. Not all terms are used.

atomic number compounds electrons ionsisotopes molecules neutrons protons

56 Matter and Atoms

Chapter Test B continued


element



resulting in theformation of

are called

11. , 12. , 13. ,

which is thesame as its

14. . 15. . 16. .

Name Date Class

Short AnswerDirections: Respond to each statement on the lines provided.

17. Compare and contrast homogeneous mixtures and heterogeneous mixtures.

18. Relate the amount of energy an electron has to its location within the electron cloud.

19. Summarize Write a sentence that describes the relationship between elements andcompounds.

Concept ApplicationDirections: Answer each question or respond to each statement on the lines provided. Use complete sentences.

20. Infer A neutral iron atom has an atomic number of 26. How many electrons does thisatom have? Explain the reasoning you used to arrive at your answer.

21. Classify If the components of a type of matter can be separated by evaporation, is thematter classified as a mixture or compound? Explain your classification.

Matter and Atoms 57

Chapter Test B continued

Name Date Class


1. Which statement can be used to describe a heterogeneous mixture but NOTa solution?A. Its parts are evenly mixed.B. Its individual parts can be seen.C. It contains a solvent and solute.D. Its components are chemically bonded.

2. Which symbol is NOT a chemical formula of a compound?A. H2

B. CO2

C. H2OD. NaCl

3. Which statement about the structure of an atom is correct?A. Protons and electrons always occur as pairs.B. The nucleus contains protons and neutrons.C. All charged particles are located in the nucleus.D. Neutrons move around in an area around the nucleus.

4. Trail mix and salt water could be classified asA. mixtures.B. solutions.C. substances.D. compounds.

5. Two atoms of the same element cannot have different numbers ofA. protons.B. particles.C. neutrons.D. electrons.

6. In which situation will the starting components NOT retain their individualproperties?A. Fruit is mixed to make fruit salad.B. Salt dissolves in water to make salt water.C. Hydrogen and oxygen bond to make water.D. Copper and zinc are combined to make brass.

Chapter Test C

58 Matter and Atoms

Name Date Class

CompletionDirections: One each line, write the term that correctly completes each sentence.

7. The parts of a(n) are evenly mixed but not bondedtogether.




Interpreting a DiagramDirections: Complete this concept map by writing the correct term on the line.

Matter and Atoms 59

Chapter Test C continued


element



resulting in theformation of

are called

11. , 12. , 13. ,

which is thesame as its

14. . 15. . 16. .

Name Date Class

Short AnswerDirections: Answer each question or respond to each statement on the lines provided.

17. Formulate a single question you might ask about the components of a mixture youcannot physically examine to determine whether the mixture is a homogeneousmixture or a solution.

18. Relate Write a sentence that describes the relationship between the following threefactors: an electron’s distance from the nucleus, the attraction between the electron andthe nucleus, and the amount of energy the electron has.

19. Summarize the relationship between elements and compounds.

Concept ApplicationDirections: Respond to each statement on the lines provided. Use complete sentences.

20. Analyze Sodium is an element with the chemical symbol Na and the atomic number 11.How many electrons does the ion Na+ have? Explain your reasoning.

21. Develop a plan to classify a clear liquid as a mixture or compound based upon themethods that can be used to separate its components.

60 Matter and Atoms

Chapter Test C continued

Lesson 2 | The Structure of Atoms - Ms. Holm...

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